1. Field of the Invention
This invention relates generally to apparatus for translating circular movement into reciprocal lineal movement, and more specifically to a crank mechanism for imparting reciprocal lineal movement to a member through forward and reverse strokes with dwell periods at each end of its stroke.
2. Description of the Prior Art
It is generally well known in the art to provide apparatus for imparting reciprocal lineal movement to a member with dwell periods at each end of its stroke. Exemplary apparatus can be found in the motion picture and photographic printing art for intermittently feeding a film through a film gate. Such apparatus, of which U.S. Pat. Nos. 1,825,254 and 3,044,676 are exemplary, obtain the reciprocal movement of a member and dwell periods at each end of its stroke by means of interacting cams. One disadvantage of such apparatus, particularly at high speed application, is that the cam and cam follower parts are subject to heavy wear resulting in substantial maintenance and replacement costs.